Postdoctoral Fellowship Study of X-Ray Optical Mammography


Book Description

A number of feasibility measurements were performed to assess the x-ray imaging properties of two capillary optics for digital mammography. Optic 1, used in year one, had input and output diameters of 4.15 mm and 7.5 mm, respectively, . Optic 2, used in year two had input and output diameters of 3.62 mm and 6.83 mm, respectively. A mammographic scanning system was constructed to allow imaging of a larger field for some of the measurements. Optic 1 showed good primary transmission, 46%. Optic 2 had better linearity at mammographic energies. Images of a Lucite contrast detail phantom, using a lead blocker, showed that both optics provide an increase in image contrast with a contrast improvement of approximately 1.7, and a reduction of scatter fraction to 0.02. The limiting resolution for the CR phosphor plate system was increased to about 8.5 1p/mm, with an improvement of the MTF at all spatial frequencies. Clinical training was received by the postdoctoral fellow.




Postdoctoral Fellowship Study of X-Ray Optical Mammograph


Book Description

A number of feasibility measurements of the x-ray imaging properties of a capillary prototype optic for digital mammography were performed. The capillary prototype optic had input and output diameters of 4.15 mm and 7.5 mm, respectively. A mammographic scanning system was constructed to allow imaging of a larger field for some of the measurements. The optic showed good primary transmission (46%) at mammography energies. Images of a lucite contrast detail phantom, using a lead blocker, showed that the optic provides an increase in image contrast with a contrast improvement of 1.72 and a reduction of the scatter fraction to 0.018. The limiting resolution for the phosphor plate system (CR) was measured through the modulation transfer function (NTF). The 5% MTF for the stationary and scanned optic was 9 lp/mm and 8.4 lp/mm, respectively, compared with 5.4 lp/mm without the optics using a 0.3 mm focal spot and optimal magnification.




X-ray Phase-Contrast Imaging Using Near-Field Speckles


Book Description

This thesis presents research on novel X-ray imaging methods that improve the study of specimens with small density differences, revealing their inner structure and density distribution. Exploiting the phase shift of X-rays in a material can significantly increase the image contrast compared to conventional absorption imaging. This thesis provides a practical guide to X-ray phase-contrast imaging with a strong focus on X-ray speckle-based imaging, the most recently developed phase-sensitive method. X-ray speckle-based imaging only requires a piece of abrasive paper in addition to the standard X-ray imaging setup. Its simplicity and robustness combined with the compatibility with laboratory X-ray sources, make it an ideal candidate for wide user uptake in a range of fields. An in-depth overview of the state of the art of X-ray speckle-based imaging and its latest developments is given in this thesis. It, furthermore, explores a broad range of applications, from X-ray optics characterisation, to biomedical imaging for 3D virtual histology and geological studies of volcanic rocks, demonstrating is promising potential. Moreover, the speckle-based technique is placed in the context of other phase-sensitive X-ray imaging methods to assist in the choice of a suitable method, hence serving as a guide and reference work for future users.




Grating-Based X-Ray Phase-Contrast Mammography


Book Description

This thesis offers an accessible guide to biomedical phase-contrast imaging with over 20 radiographic illustrations. It focuses on research to improve radiography, and particularly mammography applications, by using a novel X-ray imaging modality that exploits the wave-nature of X-rays, rather than just their absorption in tissue. Further, it explores a broad range of potential applications – from the assessment of breast cancer and the evaluation of microcalcification clusters, to the examination of renal stones. X-ray imaging is an indispensable tool in modern medical diagnostics, and ranges from simple radiography applications to advanced CT imaging protocols. This novel phase-contrast approach has the potential to deliver significantly improved diagnostic information, also and especially in cases where mammography is used for screening purposes. The thesis is based on several studies conducted by the author – working in close interdisciplinary cooperation with medical doctors at two university clinics in Munich – and successfully demonstrates this diagnostic potential in pre-clinical experiments.




Physics of Mammographic Imaging


Book Description

Due to the increasing number of digital mammograms and the advent of new kinds of three-dimensional x-ray and other forms of medical imaging, mammography is undergoing a dramatic change. To meet their responsibilities, medical physicists must constantly renew their knowledge of advances in medical imaging or radiation therapy, and must be prepared to function at the intersection of these two fields. Physics of Mammographic Imaging gives an overview on the current role and future potential of new alternatives to mammography in the context of clinical need, complementary approaches, and ongoing research. This book provides comprehensive coverage on the fundamentals of image formation, image interpretation, analysis, and modeling. It discusses the use of mammographic imaging in the detection, diagnosis, treatment planning, and monitoring of breast cancer. Expert authors give a balanced summary of core topics such as digital mammography, contrast-enhanced mammography, stereomammography, breast tomosynthesis, and breast CT. The book highlights the use of mammographic imaging with complementary breast imaging modalities such as ultrasound, MRI, and nuclear medicine techniques. It discusses critical issues such as computer-aided diagnosis, perception, and quality assurance. This is an exciting time in the development of medical imaging, with many new technologies poised to make a substantial impact on breast cancer care. This book will help researchers and students get up to speed on crucial developments and contribute to future advances in the field.




Lange Q&A


Book Description

Lange Q&A: Mammography Examination is a comprehensive study guide for the ARRT’s Mammography Examination. The book summarizes the mammography curriculum in a clear and concise format and includes review Q&A plus two complete practice exams. With this book, radiographic technicians get the practice they need to pass the registry examination with flying colors.




Dual Modality Imaging System for Breast Cancer Research


Book Description

In the 25-40% of the general female population with radiodense breast parenchyma, clinically occult lesions may be invisible in the screen-film mammogram. Even if suspicious masses are detected, determination of the benign or malignant nature of a mass is often impossible from the x-ray image. There is thus a need for diagnostic procedures that can noninvasively help characterize suspicious breast lesions. Scintimammography is an imaging technique that shows promise as an adjunct diagnostic tool in problem solving mammography, for monitoring recurrence after surgery, and in the assessment of multidrug-resistance. However, because clinical Anger cameras have only moderate spatial resolution and are difficult to position close to the breast, small lesions are difficult to detect. In addition, no direct means exists of correlating mammographic and scintigraphic information because of the significantly different shape of the breast in mammography (compressed) and scintimammography (prone, pendulant). We are developing an imaging system that overcomes these problems by combining digital x-ray mammography and gamma emission scintigraphy in a single, integrated system. The system is mounted on a standard upright mammography unit, and can easily be placed in a typical mammography room, providing accessibility even for small breast imaging clinics not associated with major medical centers.







Mammography and Breast Imaging: Just The Facts


Book Description

The perfect review tool for radiologic technologists certifying or recertifying. Following the guidelines specified by the American Registry of Radiologic Technologist (AART) Exam, the book includes all breast imaging modalities and techniques as well as questions for self-assessment.




A Diffuse Optical Tomography System Combined with X-ray Mammography for Improved Breast Cancer Detection


Book Description

The central thesis of this dissertation states that optical imaging of diffuse tissues must be combined in co-registration with a recognized gold standard of mammographic screening, i.e. X-ray mammography, to gain wide acceptance in the clinical environment. This multi-modality imaging approach promises to overcome the deficiencies of both imaging modalities by drawing on the strengths of each. Functional and structural image contrast would be provided by optical and high-resolution structural contrast by X-ray. Furthermore, the structural information provided by X-ray could be used to improve the optical image reconstruction by providing boundary information and soft constraints for weakly correlated structural contrast. Ultimately, image-processing techniques could be developed to provide the radiologist with a three-dimensional image indicative of both optical and X-ray contrast that would provide much greater information content than either modality alone.